If you had enough money to buy one volume of any manga which one would you but?

Sorry for tricking but this topic was so I could decide on which volume I should buy from a certain manga, and I have decided to buy Bleach volume 56.
Didn't want the topic to be closed so I pretended.

Id buy Blame! I love the series but some of the volumes are over $100 because they have been out of print for years.

You ever try his other works? They're great as well.

As for me - it'd probably be the Again!! manga. I mean, I could always import it - but it costs a lot to do so and I really only do that with manga that don't have ten or more volumes. Birdy the Mighty II being an exception...